Scientists directly observe diffusion behavior within individual nanostructures

In recent years, organic semiconductor materials have attracted considerable attention as key components for next-generation photoenergy conversion devices and organic solar cells due to their light weight and mechanical flexibility. A crucial factor determining their performance is how photoexcited excitons migrate between molecules, that is, the process of exciton diffusion. However, previous studies have provided only ensemble-averaged information, making it difficult to directly observe the diffusion behavior within individual crystals or nanostructures.